Single diagnostic pacing maneuver for supraventricular tachycardia

BackgroundDiagnostic supraventricular tachycardia (SVT) features and pacing maneuvers tend to be specific but insensitive. Therefore, diagnosis often requires the integration of multiple pieces of information and/or pacing maneuvers, which adds to the complexity of catheter ablation procedures.ObjectiveThe purpose of this study was to determine if a single diagnostic pacing maneuver, namely, ventricular overdrive pacing including a basal pacing site near the earliest atrial activation, provides a definitive SVT diagnosis in nearly all patients.MethodsSixty-seven consecutive patients with SVT undergoing catheter ablation at two institutions were prospectively studied.ResultsOverdrive ventricular pacing provided the correct diagnosis in 91% of all patients and in 100% of patients when pacing accelerated the atrium to the pacing cycle length. Fusion due to wavefront collision in the ventricles or distal conduction system was 73% sensitive and 100% specific for accessory pathway-mediated SVT. Basal pacing was superior to pacing from the right ventricular apex for distinguishing accessory pathway-mediated SVT from AV nodal reentrant tachycardia.ConclusionOverdrive ventricular pacing is a highly effective single diagnostic pacing maneuver for sustained SVT. Basal pacing sites near the earliest atrial activation are superior to the right ventricular apex.